Wondering what in the world these red bugs are?? They seem to stay piled up together, on my butterfly weed. Can't really see that they are doing any damage just yet but would like to know if they plan on it.
They're aphids and the milkweeds seem to attract plenty of them. You can try to battle them by hosing them off with a strong stream off water or maybe a mild soap solution. Anything stronger might harm your caterpillars.
They're hard shelled? Maybe I jumped the gun... aphids wouldn't have a hard shell. Maybe they're some sort of plant bug? If that's the case it will probably take more than soapy water to get rid of them. Try to knock the bugs off into a bucket of water mixed with a little ammonia.
Yikes! I have noticed that as the days go by they do seem to be getting bigger. But then again I can't tell that they are doing any real damage to the butterfly weed. They just pile up on one of the seed pods and sit there.